Sheet transfer apparatus



Oct. 5, 1965 H. T. HAWKES 3,209,924

SHEET TRANSFER APPARATUS Filed July 2, 1957 2 Sheets-Sheet 2 Fig. 8.

131 L I /1 f-r\=; 125* INVENTOR. TEQBORE HAWKES flan/a0?! WW" 9i 9 ATTQRNEYS United States Patent 3,209,924 SHEET TRANSFER APPARATUS Howard Theodore Hawkes, Cape Elizabeth, Maine, as-

signor to Southworth Machine Company, Portland, Maine, a corporation of Maine Filed July 2, 1957, Ser. No. 669,555 9 Claims. (Cl. 214-8.5)

This invention relates to an improved apparatus for unstacking and restacking piles of flexible sheets, whereby each pile may be individually treated. It is particularly directed to an improved, wheeled, transfer table for use in feeding piles of paper sheets to a guillotine type trimmer and delivering the trimmed piles to a restacking location.

It has heretofore been proposed to use a pair of horizontally movable tables, each having a plurality of pressure sensitive air nozzles in the upper face thereof, one table for unstacking and feeding a paper trimmer, the other table for unloading the trimmer and restacking. Such tables have had downwardly foldable extensions with blunt ends for increasing the area of the table top but there have been no air nozzles in such extensions. Such tables have had leg members or supports under all four sides of a rectangular table top and the table top has been of opaque material.

It has also been proposed in US. Patent No. 2,089,890 to Graf, issued August 10, 1937, to provide a sheet piler buggy, or transfer table, of inverted U shaped construction arranged to straddle a separate propelling unit and having a rotatable top for supporting a removable pallet or platform.

It has been the custom in the paper industry to locate a stack of sheets on a pallet near a paper trimmer with the pallet resting on a lift table and the lift table in a low position. An empty pallet has been mounted on another lift table near the trimmer with the lift table in a high position. The feed transfer table has then been rolled on tracks from the trimmer up to the stack and at least two operators have had to manually segregate the topmost pile of sheets from the stack and slide the same manually onto the air cushion top of the transfer table. The feed transfer table has then been rolled up to the trimmer Where the trimmer operator can slide the pile into the trimmer. Meantime the lift table supporting the stack has been raised to position the next successive top pile at the height of the top of the transfer table.

After trimming, the trimmed pile has been slid from the trimmer onto the air cushion of a delivery transfer table and the delivery transfer table has been rolled on tracks up to the empty pallet and its lift table. At least two operators have then had to manually slide the trimmed pile off the air cushion table top onto the pallet and up against a jogging board. It has been most difficult to secure a neat stack on the empty pallet in View of the drop off the blunt end of the table and the lateral forces exerted on the pile to move it off the table. Usually there is a single sheet of less valuable paper under each stack or pile for receiving any slide marks or for receiving wax marks from the bed of the trimmer and it has been difficult to strip this sheet after trimming without disturbing the integrity of the pile carried thereon. The lift table supporting the originally empty pallet is lowered after the deposit thereon of each successive trimmed pile to the level required for receiving the next successive trimmed pile.

The principal object of this invention is to provide an improved apparatus for unstacking, trimming and restacking piles of flexible sheets which reduces the number of operators required and enables sheets of large area to be 3,269,924 Patented Oct. 5, 1965 ice transferred by a single unstacking operator and a single restacking operator.

Another object of the invention is to provide a transfer table adapted to straddle a stack, pallet and/or lift table while segregating or depositing a pile of sheets by means of a unitary, table top which is horizontally immovable relative to the wheeled frame of the table.

A further object of the invention is to provide a straddle type transfer table having leg members on three sides but not on the fourth side and having novel overhanging ing, inclined ramp means on the fourth side of a unitary table top for gradually raising a stack of sheets or depositing a pile of sheets gently on a stack.

Still another object of the invention is to provide a straddle type transfer table having a table top supported at a predetermined height by a wheeled frame to define a stack straddle space, together with means carried by the table for raising the table top to heights above said predetermined height to thereby increase the height of the straddle space under said top.

A still further object of the invention is to provide a straddle type transfer table with self contained pneumatic means for raising the table top to desired heights, for creating an air cushion on the upper face of the table top and on a ramp-like projection and for self propelling of the table along horizontal tracks.

A still further object of the invention is to provide a straddle type transfer table with a driven rotatable suction roll in the top face thereof and mounted in a slot whereby the under sheet of a stack or pile may be stripped and discharged below the table top as a pile of sheets is slid over the roll onto the table top.

Other objects and advantages of the invention will be apparent from the claims, the description of the drawings and from the drawings in which a preferred embodiment thereof is illustrated.

In the drawings:

FIG. 1 is a side view of a transfer table according to the invention with parts broken away and a raised position of the table top shown in dotted lines.

FIG. 2 is a rearward end view of the device shown in FIG. 1.

FIG. 3 is a plan view of the device shown in FIG. 1 with portions of the table top broken away.

FIG. 4 is a fragmentary side view of the forward, or leading, end of the transfer table shown depositing a pile during restacking.

FIG. 5 is an enlarged side view, in section, of the table top shown in FIGS. 1 to 4.

FIG. 6 is a view similar to FIG. 5 showing a modified form of table top.

FIG. 7 is a view similar to FIG. 5 showing a driven rotatable suction roll in the table top of FIG. 5.

FIG. 7A is a view similar to FIG. 1 of a table in accordance with the invention driven electrically rather than pneumatically and having flexible means for driving the suction stripping roll or the friction feed roll.

FIG. 8 is an enlarged end view, in section, of the suction stripper roll shown in FIG. 7.

FIG. 9 is a side elevation of a typical paper trimmer layout showing the method of stacking, trimming and restacking of the invention.

FIG. 10 is a view similar to FIG. 9 showing another stage of the method.

FIG. 11 is a fragmentary, enlarged side elevation of the leading end of a feed transfer table having the table top shown in FIG. 6 and about to wedge or pry its way under the topmost pile of a stack.

As shown in the drawings, 20 is a transfer table in accordance with the invention, the table 20 having a table top 21 and a table top supporting member 22.

Table top is preferably rectangular in outline, horizontal and of greater area than the area of the rectangular flexible sheets such as 23 in the stack 24. Table top 20 includes two longer sides 25 and 26 and two shorter sides 27 and 28 and is supported at about waist level, at a predetermined height above the floor 29 by the member 22.

The table top supporting member 22 is of recumbent U shape, rather than of inverted U shape and includes spaced apart vertical side supports 31 and 32 each under a longer side 25 or 26 of the table top and a similar vertical support 33 under one shorter side such as 27 of the table top. There is no vertical support or obstruction of any kind under the short side 28 of table top 21, this being the open end of the recumbent U shaped support and forming an entrance opening 34 for receiving a stack. The table top 20 and supporting member 22 jointly define a straddle space 35 large enough to accommodate a Waist high stack such as 24, together with a pallet such as 36 and a lift table such as 37 thereunder. The straddle space 35 is also unobstructed laterally from the opening 34 to the rearward end support at 33 and it is of a uni form horizontal area greater than the area of the sheets 23, stack 24, pallet 36 and lift table 37. Member 22 is thus a rectangular frame having an open end at 34 and an open interior at 35, the frame being covered by the table top 20.

Table top 29 is preferably skeletonized and transparent in order that the straddle space 35 and straddle opening 34 may be viewed by an operator in performing the unstacking and restacking operation. A transparent sheet 40 having a flat, smooth upper face 41 is supported on a grid 42 formed of hollow metal air conduits such as the longitudinal conduits 43 and the spaced lateral conduits 44. A plurality of pressure sensitive air nozzles such as 45 are distributed about the sheet 40, each fed by a conduit and supported therein. Each nozzle 45 includes a ball 46 and coil spring 47 mounted in a socket 48, the upper portion of each ball extending through a hole such as 49 pierced in sheet 40. The conduits of grid 41 are connected by a flexible air conduit 51 to an air control valve 52 mounted at the rear of the support member 22. The forward or leading edge portion 53 of the table top 21, extending along the short side 28 above the straddle opening 34, is inclined downwardly from the level of the upper sheet 40 to the level of the lower transparent sheet 54, and terminates in a relatively sharp pointed leading edge 55. Preferably the inclined forward edge portion or ramp, as shown, is formed on a fixed projection 56 of table top 21, the projection 56 extending beyond the forward ends of side support members 31 and 32 and overhanging the opening 34.

The area of the table top 21 is unobstructed and large enough to support the maximum area of sheet to be carried on table 20 and projection 56 is not intended to increase that area as in prior devices. Instead, projection 56 supports a pile 57 of sheets only when the pile is being wedged onto the table top or slid off the table top. Because of the antifriction air cushion created under the pile by the air nozzles 45, it is only necessary to gently nudge the pile down the inclined upper face 58 of projection 56 whereupon gravity tends to urge the pile completely off the table top. Similarly in sliding a pile up the inclined face 58 of projection 56, the line of air nozzles 59 in the projection 56 tends to overcome friction and enable the pile to be slid onto the table top with negligible force.

The table top supporting member, or frame, 22 is horizontally movable preferably by means of the wheels 61 travelling on tracks such as 62. Instead of solid vertical supports the side supports 31, 32 and 33 are skeletonized as shown in order to give the operator a clear view of the straddle space 35. The side supports 31, 32 and 33 include lifting means in the form of upstanding, hollow fluid cylinders 63, 64, 65 and 66 connected at the top by horizontal frame members 67, 68 and 69 and connected at the bottom by horizontal hollow members 71, 72 and 73 forming fluid conduits. Conduits 71, 72 and '73 connect with the bottom of the cylinders and are in turn connected by the conduit 74 to a valve 75 on the rearward frame member 68. Guide mechanism in the form of vertical pistons '76, 77, 78 and 79 extend downwardly from table top 21 and are slideable in cylinders 63, 64, 65 and 6 6whereby a fluid such as air supplied through a valve 75 raises the table top 21 to various desired heights up to shoulder height. It is thus possible for the transfer table of this invention to straddle a shoulder high stack, remove the topmost pile therefrom, lower the pile to waist height for trimming and restacking and continue to remove the next successive topmost piles from such a stack. While the wheeled straddle table 20 is horizontally movable and while the table top 21 is vertically movable, the table top 21 is horizontally immovable, relative to the wheeled member, or frame, 22, regardless of the heights to which the top is raised. As best shown in FIGURES 4, 9 and 11 the ramp means on the edge of the table top 21 is firmly supported against tilting downwardly into contact with the topmost sheet of a straddled stack by the forward ends of the side frame members when at waist level and by the pistons of the lift mechanism when raised to shoulder level.

Transfer table 29 is self propelled preferably by an air motor 81 carried by the support member 22 and aligned with a side support such as 31. The motor 81 comprises a double acting cylinder 82, piston 83, valve 84 and crank arm 85, the crank arm 85 being operably connected by a counterweighted wheel 61. Air under pressure is supplied to valve 84 by a conduit 86 leading to a control valve 87 mounted on the frame member 68. Valve 84 interchanges the supply and exhaust ports to cause reversal of direction of the table and is operable by the foot pedal 88.

As shown in FIGS. 6 and ll a modified form of table top such as 91 may be provided for use in unstacking piles of sheets such as 92 from a stack 93. The operator first inserts a cross bar such as the angle iron 94 under the edge of the lower sheet of the topmost pile 92 so that the opposite ends of the iron 94 protrude from the stack. The projection 95 of the table 91 includes a driven roller 96 and a pair of parallel, forwardly projecting spars 97 and 98 laterally spaced apart a distance greater than the width of stack. 93. The upper faces 99 and 100 of the spars 97 and 98 constitute ramps and incline downwardly from the plane of the flat upper face of table top 91 to a forward terminus located in a plane which may be in, or slightly below the plane of the flat lower face of the top 91. Roller 96 is friction faced and rotated in the direction of the arrow at a greater surface speed than the speed of advance of the table. The advance of table top 91, as the table straddles stack 93, causes the spars 97 and 98 to lift the opposite protruding ends of pile separator bar 94, with a wedging or prying action, until the iron 94 moves over roller 96 onto table top 91. The lowermost sheet of pile 92 is thus lifted away from the stack to create an opening for roller 96 and is then deposited on the friction face of the roller. As the roller 96 rotates at greater speed than the table is advancing, it not only pulls the pile 92 onto the table top 91 but maintains tension on the undersheets of the pile to prevent sagging thereof. This in turn keeps the leading and trailing edges of the pile 92 in plumb condition.

Continued advance of the straddle table causes the top most pile 92 to become progressively more supported on the air cushion of the table top with the angle iron 94 either remaining in place or being removed by an operator. When, as is sometimes the case, the trimmer includes. a slot in its bed, it is desirable to leave the iron 94 in place so that it may bridge such a slot to prevent the leading edges of the pile from entering the. same.

As best shown in FIGS. 7 and 8 a modified form of table top 102 includes a slot 103 at least co-extensive in length with the corresponding dimension of the sheets in the stack. A driven rotatable suction roll 104 is journalled by means of stub shafts such as 105 and 106 at the opposite ends of slot 103 with the upper curved face 107 of the roll substantially coplanar with the upper face 108 of the table top 102. Roll 104 is hollow and the curved face thereof is perforated, there being a fixed wiper 109 within the roll. One stub shaft such as 105 is hollow and connects the interior of roll 104 to a flexible conduit 111, the conduit 111 leading to a valve 112 on frame member 68. Valve 112 is connected by a flexible conduit 113 to a source of air suction of any well known type such as a tank, not shown, whereby suction may be created in the perforated roll 104 when desired. It will be understood that each pile 92 or stack such as 93 is usually placed on a disposable paper sheet 114 in order to protect the lowermost sheets of the stack from pallet marks and the like. The suction stripper roll 104 adheres to such a disposable sheet when the lowermost pile of the stack is slid onto or off table top 102 after trimming. The roll 104 guides the sheet 114 down into the slot 103 and the wiper 109 masks the suction well below the slot to release the sheet 114 to fall onto the floor below the table.

In addition to the flexible suction conduit 113, each table is connected by a flexible air conduit 115 leading to valves 52, 75 and 87 from a suitable source of air pressure such as a tank, not shown.

As shown in FIG. 7A, instead of pneumatic means at the rear of the table for advancing the same, electrical drive means at the side of the table may be provided, outside the straddle space, or frame interior 35. The table 140 is similar to table 20 but the table 141 may include the driven friction roll 96 or the driven suction roll 104. A reversible electric motor 142 and gear reducer 143 are carried on a bracket 144 fixed to the table support 145 to occupy space outside the straddle opening and the straddle space of the table near the front thereof. Sprockets 146 and 147 and chain 148 connect the adjacent wheel 160 of the table 140 to the reducer 143 and suitable switch means well known in the art and not shown are provided to cause the motor to advance or retract the table at a predetermined speed.

A flexible power shaft 149 connects the reducer 143 to the friction roller 96 and is arranged to rotate the roll at greater surface speed than the speed of advance of the table. If a suction roll 104 is desired, instead of the roller 96, the flexible shaft 149 is used to drive the same in a similar manner.

In operation a table 122 is placed on a track leading from a stack location 120 to the feed portion of a trimmer 121 and a similar table 20 is placed on a track leading from the delivery position of the trimmer 121 to a restacking location 123. In the illustration, the feed and delivery portion of the trimmer 121 is identical so that the tables are back to back on a single straight track 62 extending along the front of trimmer 121. It will be obvious that any suitable treatment operation can be performed on the piles of sheets at the trimmer location. A lift table 37, of any suitable type, carrying an empty pallet 36 at about waist level is provided at the restacking location 123 and a similar lift table 124 carrying a similar pallet 125 at floor level supports a waist high stack 126 of flexible sheets 127 at the stack location 120.

A single operator handles trimmer 121 and each transfer table 20 and 122 is handled by a single operator. Table 122 with its downwardly inclined, ramp-like projection 156 is advanced over the stack 126 by straddling the same while the projection 156 wedges its way under pile 128 and through the stack from one end to the other.

Preferably the flat underface of the table top is spaced above the level of the top sheet of the stack under pile 128 in order not to crumple the same, the leading portion of pile 128 being manually lifted up onto the inclined projection 156 by means of an angle iron such as 94. A modified form of table top such as shown at 91 may also be used if desired. The topmost pile 128 of sheets is thus lifted onto the air cushion table top 129 of table 122. The table 122 is then moved to the trimmer 121 where the pile 128 is slid onto the deck 131 thereof for trimming. Table is positioned in front of trimmer 121 to slideably receive the trimmed pile 128 on its air cushion table top 21. Table 20 is then moved to a position straddling restacking location 123, lift table 37 and pallet 36.

The lift table 37 is then raised, or the table top 21 lowered, to cause the flat underface of the table top to clamp any sheets already on pallet 36 in place. This prevents crumpling of the top sheets during the addition thereto of the pile 128. File 128 is then urged 0E table top 21, down the inclined upper face 58 of projection 56 into contact with the jogging board 137, with the leading edges of the sheets still plumb. The lift table 37 may then be lowered or the table top 21 may be raised slightly to unclamp from the stack whereupon the table 20 is withdrawn from under pile 128 to complete the restacking thereof.

Lift table 124 is then raised and lift table 36 is lowered a distance equal to the depth of the pile 128 to bring the next successive topmost pile 132 to the level of table top 129 and to lower pile 128 for receiving the pile 132. The unstacking, trimming and restacking steps outlined above are repeated until the entire stack 126 has been trimmed and restacked at location 123. Because of the means for raising the table tops 21 and 129 incorporated into the tables 20 and 122, a stack such as 126 may be shoulder, or head high, and still be unstacked and restacked without requiring an operator on each side of the stack. In such case the table top 129 after pneumatically and progressively wedging the topmost pile from the stack, is lowered to the level of the deck 131 for the trimming operation and after the trimming operation, the table top 21 can be raised to shoulder or head height for restacking purposes.

During the entire operation the stacks straddled by the tables may be viewed by the operator through the transparent skeletonized table tops and through the openings such as at 133 in the skeletonized table top supporting members. The guide mechanism and lifting means of the tables are aligned with each opposite longer side of the table top and supporting member or outside the same and do not reduce the inside width of space 35 or increase the outside width of the table 20.

I claim:

1. A pile transfer table comprising a rectangular wheeled frame of predetermined height having an open end and an open interior for receiving and straddling an entire stack of flexible sheets of said predetermined height; a unitary table top mounted on, and covering said frame for slidably supporting a pile of said flexible sheets, said table top having flat, parallel upper and lower faces free of barriers to the sliding of a pile therealong, ramp means in the form of a pair of spars, each on an opposite side of the open end of said frame and projecting therebeyond for engaging the opposite ends of a pile separator bar; a friction feed roll journalled within said table top proximate the open end of said frame, the upper portion of said roll only extending slightly above the plane of the upper face of said table top for engaging the bottom sheet of a pile; self propelling means on said frame mounted outside the interior thereof, for moving said table toward and away from straddle position over a stack at a predetermined surface speed and drive means mounted on said table outside the interior of said frame for rotating said friction feed roll at a surface speed greater than the surface speed of said table.

2. A horizontally movable transfer table for use in stacking and unstacking piles of flexible sheets, said table comprising a unitary, substantially flat, unobstructed table top for slidably receiving and supporting a pile of said sheets, said top having parallel upper and lower faces of greater area than the area of the sheets in said pile; a pair of side supporting members along two opposite sides and an end supporting member along one end of said table top adapted to support said top at a fixed height, said side supporting members being spaced apart a distance greater than the corresponding dimension of a stack of said sheets to define with said top an unobstructed stack straddle opening at the other end of said top and to define an unobstructed stack receiving space beneath said top accommodating an entire stack of said sheets; ramp means integral with and fixed to said other end of said table top, said means comprising a pair of identical spars laterally spaced apart a distance greater than the width of said stack and having upper faces which incline downwardly from the plane of the upper face of said top to the plane of the lower face of said top for engaging and lifting a cross bar in said stack as said table straddles said stack; a plurality of pressure sensitive air nozzles distributed in spaced relation throughout the upper face of said table top; means for supplying air to said nozzles for supporting a pile of sheets resting thereon on a cushion of air; a single, friction feed roll rotatably mounted within said table top proximate said spars for engaging the under sheet of a pile and means for rotating said roll at a greater surface speed than the speed of advance of said table for pulling a pile of sheets from said stack onto said table top.

3. In apparatus for handling flexible sheets, the combination of stack lift mechanism and a horizontally movable, self propelled, wheeled transfer table, said table comprising a unitary table top having a horizontal, unobstructed, substantially flat, upper face of greater area than the area of said sheets and a lower face parallel thereto; a pair of wheeled, side-supporting members, each under an opposite side, and an end supporting member under one end, of said table top adapted to support said top at a predetermined height, said side supporting members being spaced apart a distance greater than the corresponding dimension of a stack of said sheets to straddle each opposite side thereof with said table top overlying the entire stack; means on said table for creating an air film on said upper face; self propelling means, on said table, for moving said table horizontally toward and away from said stack lift mechanism and ramp means on said table top, projecting beyond the ends of said side support members and having an upper face inclining downwardly from the plane of the upper face to the plane of the lower face of said top, said ramp means comprising a pair of identical spars, each on an opposite side of said table top, adapted to extend along each opposite side of a stack in advance of the remainder of said table.

4. In apparatus for handling flexible sheets the combina tion of stack lift mechanism and a horizontally movable, self propelled, wheeled transfer table, said table comprising a unitary table top having a horizontal, unobstructed, substantially flat, upper face of greater area than the area of said sheets and a lower face parallel thereto; a pair of wheeled, side-supporting members, each under an opposite side, and an end supporting member under one end, of said table top adapted to support said top at a predetermined height, said side supporting members being spaced apart a distance greater than the corresponding dimension of a stack of said sheets to straddle each opposite side thereof with said table top overlying the entire stack; means on said table for creating an air film on said upper face; self propelling means, on said table, for moving said table horizontally toward and away from said stack lift mechanism and ramp means on said table top, projecting beyond the ends of said side support members and having an upper face inclining downwardly from the plane of the upper face to the plane of the lower face of said top, said ramp means comprising a pair of identical spars, laterally spaced apart a distance greater than the Width of said stack for engaging and lifting a cross bar therein as said table straddles said stack, a single, friction feed roll rotatably mounted between said spars proximate said table top and means for rotating said roll at a greater surface speed than the speed of advance of said table for pulling a pile of sheets from said stack onto said table top.

5. In apparatus for handling flexible sheets, the combination of stack lift mechanism, for raising and lowering a stack of said sheets, and a self propelled, pile transfer table, said table comprising a rectangular wheeled frame of predetermined height having an open end and an open frame interior for receiving and completely straddling a stack of said predetermined height supported on said lift mechanism; a unitary, table top horizontally immovable on, and covering said wheeled frame, said top having flat parallel upper and lower faces free'of barriers to the sliding passage of said sheets; self propelling means on said frame, mounted outside said frame interior for moving said table horizontally toward and away from a straddle position over a stack supported on said lift mechanism and a pair of identical, transversely spaced, spars each on an opposite side of the open end of said frame and having an inclined upper face, said spars extending along each opposite side of a stack in advance of the remainder of said transfer table.

6. In apparatus for handling flexible sheets, the combination of stack lift mechanism, for raising and lowering a stack of said sheets, and a self propelled, pile transfer table, said table comprising a rectangular Wheeled frame of predetermined height having an open end and an open frame interior for receiving and completely straddling a stack of said predetermined height supported on said lift mechanism; a unitary, table top horizontally immovable on, and covering said wheeled frame, said top having flat parallel upper and lower faces free of barriers to the sliding passage of said sheets; self propelling means on said frame, mounted outside said frame interior for moving said table horizontally toward and away from a straddle position over a stack supported on said lift mechanism; at least one friction feed roll extending transversely within said table top proximate the open end of said frame, the upper portion only of said roll extending slightly above the plane of the upper face of said table top and means mounted on said frame, outside said frame interior, for rotating said roll at a greater surface speed than the surface speed of said table for pulling a pile of sheets from a stack onto the upper face of said table top.

7. In apparatus for handling flexible sheets, the cornbination of stack lift mechanism, for raising and lowering a stack of said sheets, and a self propelled, pile transfer table, said table comprising a rectangular wheeled frame of predetermined height having an open end and an open frame interior for receiving and completely straddling a stack of said predetermined height supported on said lift mechanism; a unitary, table top horizontally immovable on, and covering said wheeled frame, said top having flat parallel upper and lower faces free of barriers to the sliding passage of said sheets; self propelling means on said frame, mounted outside said frame interior for moving said table horizontally toward and away from a straddle position over a stack supported on said lift mechanism; power operated lift means mounted on said table outside said frame interior for raising and lowering said table top relative to said frame; a friction feed roll journalled within said table top with its upper portion extending slightly above the level of the upper face of said table top and means on said table for rotating said roll at greater surface speed than the surface speed of said table when said table top is in raised or lowered position.

8. In apparatus for handling flexible sheets the combination of stack. lift mechanism and a self-propelled, pile transfer table, said table comprising a horizontal, unitary, pile-supporting table top, having an upper face slightly greater in area than the area of said sheets; ramp means along one end of said table top, said ramp means comprising a pair of identical spars, each on an opposite side of said upper face, said spars being adapted to extend along each opposite side of a stack supported on said stack lift mechanism; a straddle frame including a pair of side support members, each extending downwardly along an opposite underside of said table top to floor level and supporting the ramp end, and the opposite end, of said table top at waist level; means connecting said table top to said frame to prevent relative movement thereof in a horizontal plane; means on said table creating an air film on the upper face of said table top, and selfpropelling means on said frame for moving said table horizontally toward and away from a straddle position over said stack lift mechanism.

9. In apparatus for handling flexible sheets the combination of stack lift mechanism and a self-propelled, pile transfer table, said table comprising a horizontal, unitary, pile-supporting table top, having an upper face slightly greater in area than the area of said sheets; ramp means along one end of said table top, said ramp means comprising a pair of identical, transversely-spaced, spars each adapted to extend along an opposite side of a stack on said stack lift mechanism, a single friction feed roll rotatably mounted between said spars with the upper portion thereof extending slightly above the plane of said upper face and means, on said table, for rotating said roll at a greater surface speed than the surface speed of said table; a straddle frame including a pair of side support members, each extending downwardly along an opposite underside of said table top to floor level and supporting the ramp end, and the opposite end, of said table top at waist level; means connecting said table top to said frame to prevent relative movement thereof in a horizontal plane; means on said table creating an air film on the upper face of said table top, and self-propelling means on said frame for moving said table horizontally toward and away from a straddle position over said stack lift mechanism.

References Cited by the Examiner UNITED STATES PATENTS 586,408 7/97 Williams 19335 1,464,513 8/23 Sutherland. 2,017,044 10/35 Graf et al 214-6 X 2,061,495 11/36 Woodruif 214-452 2,176,307 10/39 Lamb et al. 2,181,357 11/39 Chipman 2l4152 2,508,661 5/50 Campbell 2l4390 2,73 0,247 1/56 Lawson. 2,768,756 10/56 Horman. 2,815,249 12/57 Curtenius. 2,854,150 9/58 Shea. 2,947,428 8/60 Curtenius. 2,95 8,431 11/60 Curtenius. 2,960,243 11/ Beaulieu.

FOREIGN PATENTS 73 7,069 9/55 Great Britain. 740,297 11/55 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

ERNEST A. FALLER, HUGO O. SCHULZ, Examiners. 

1. A PILE TRANSFER TABLE COMPRISING A RECTANGULAR WHEELED FRAME OF PREDETERMINED HEIGHT HAVING AN OPEN END AND A OPEN INTERIOR FOR RECEIVING AND STRADDLING AN ENTIRE STACK OF FLEXIBLE SHEETS OF SAID PREDETERMINED HEIGHT; A UNITARY TABLE TOP MOUNTED ON, AND COVERING SAID FRAME FOR SLIBALY SUPPORTING A PILE OF SAID FLEXIBLE SHEETS, SAID TABLE TOP HAVING FLAT, PARALLEL UPPER AND LOWER FACES FREE OF BARRIERS TO THE SLIDING OF A PILE THEREALONG, RAMP MEANS IN THE FORM OF A PAIR OF SPARS, EACH ON AN OPPOSITE SIDE OF THE OPEN END OF SAID FRAME AND PROJECTING THEREBEYOND FOR ENGAGING THE OPPOSITE ENDS OF A PILE SEPARATOR BAR; A FRICTION FEED ROLL JOURNALLED WITHIN SAID TABLE TOP PROXIMATE THE OPEN END OF SAID FRAME, THE UPPER PORTION OF SAID ROLL ONLY EXTENDING SLIGHTLY ABOVE THE PLANE OF THE UPPER FACE OF SAID TABLE TOP FOR ENGAGING THE BOTTOM SHEET OF A PILE; SELF PROPELLING MEANS ON SAID FRAME MOUNTED OUTSIDE THE INTERIOR THEREOF, FOR MOVING SAID TABLE TOWARD AND AWAY FROM STRADDLE POSITION OVER A STACK AT A PREDETERMINED SURFACE SPEED AND DRIVE MEANS MOUNTED ON SAID TABLE OUTSIDE THE INTERIOR OF SAID FRAME FOR ROTATING SAID FRICTION FEED ROLL AT A SURFACE SPEED GREATER THAN THE SURFACE SPEED OF SAID TABLE. 